Colombian Exchange
Explanation:
1]Before 1492, Native Americans (Amerindians) hosted none of the acute infectious diseases that had long bedeviled most of Eurasia and Africa: measles, smallpox, influenza, mumps, typhus, and whooping cough, among others. In most places other than isolated villages, these had become endemic childhood diseases that killed one-fourth to one-half of all children before age six. Survivors, however, carried partial, and often total, immunity to most of these infections with the notable exception of influenza. Falciparum malaria, by far the most severe variant of that plasmodial infection, and yellow fever also crossed the Atlantic from Africa to the Americas.
A coloured transmission electron micrograph showing influenza viruses (red) at the outer surface of a host cell.
Science Photo Library/SuperStock
In the centuries after 1492, these infections swirled as epidemics among Native American populations. Physical and psychological stress, including mass violence, compounded their effect. The impact was most severe in the Caribbean, where by 1600 Native American populations on most islands had plummeted by more than 99 percent. Across the Americas, populations fell by 50 percent to 95 percent by 1650.
The disease component of the Columbian Exchange was decidedly one-sided. However, it is likely that syphilis evolved in the Americas and spread elsewhere beginning in the 1490s. More assuredly, Native Americans hosted a form of tuberculosis, perhaps acquired from Pacific seals and sea lions. But they had no counterparts to the suite of lethal diseases they acquired from Eurasians and Africans. The paucity of exportable infections was a result of the settlement and ecological history of the Americas: The first Americans arrived about 25,000 to 15,000 years ago. The domestication of species other than dogs was yet to come. So none of the human diseases derived from, or shared with, domestic herd animals such as cattle, camels, and pigs (e.g. smallpox, influenza) yet existed anywhere in the Americas. Unlike these animals, the ducks, turkeys, alpacas, llamas, and other species domesticated by Native Americans seem to have harboured no infections that became human diseases.
The Columbian Exchange greatly affected almost every society on earth, bringing destructive diseases that depopulated many cultures, and also circulating a wide variety of new crops and livestock that, in the long term, increased rather than diminished the world human population.
The Columbian Exchange greatly affected almost every society on earth, bringing destructive diseases that depopulated many cultures, and also circulating a wide variety of new crops and livestock that, in the long term, increased rather than diminished the world human population.
